On Tue, Mar 29, 2016 at 8:11 AM, Srinivas Kandagatla
<srinivas.kandagatla@xxxxxxxxxx> wrote:
> On some SOCs PORTS_IMPL register value is never programmed by the BIOS
s/BIOS/firmware/
You do plan to fix this in your firmware/bootloader, too, right?
> and left at zero value. Which means that no sata ports are avaiable for
> software. AHCI driver used to cope up with this by fabricating the
> port_map if the PORTS_IMPL register is read zero, but recent patch
> broke this workaround as zero value was valid for nvme disks.
s/nvme/NVMe/
>
> This patch adds ports-implemented dt bindings as workaround for this issue
s/dt/DT/
> in a way that DT can dictate the port_map incase where the SOCs does not
> program it already.
port_map is a Linux term.
...can override the PORTS_IMPL register in cases where the firmware
did not program it already.
>
> Fixes: 566d1827df2e ("libata: disable forced PORTS_IMPL for >= AHCI 1.3)
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> ---
> Documentation/devicetree/bindings/ata/ahci-platform.txt | 11 +++++++++++
> drivers/ata/ahci_platform.c | 4 ++++
> 2 files changed, 15 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/ata/ahci-platform.txt b/Documentation/devicetree/bindings/ata/ahci-platform.txt
> index 30df832..8165db3 100644
> --- a/Documentation/devicetree/bindings/ata/ahci-platform.txt
> +++ b/Documentation/devicetree/bindings/ata/ahci-platform.txt
> @@ -32,6 +32,10 @@ Optional properties:
> - target-supply : regulator for SATA target power
> - phys : reference to the SATA PHY node
> - phy-names : must be "sata-phy"
> +- ports-implemented : Mask that indicates which ports that the HBA supports
> + are available for software to use. Useful if PORTS_IMPL
> + is not programmed by the BIOS, which is true with
> + some embedded SOC's.
>
> Required properties when using sub-nodes:
> - #address-cells : number of cells to encode an address
> @@ -59,6 +63,13 @@ Examples:
> target-supply = <®_ahci_5v>;
> };
>
> + sata0: sata@29000000 { /* Qualcomm APQ8064 */
Do you really need another example just for this?
> + compatible = "generic-ahci";
Where's your chip specific compatible string? You would not require a
DT update to fix this if you had that.
> + reg = <0x29000000 0x180>;
> + interrupts = <GIC_SPI 209 IRQ_TYPE_NONE>;
> + ports-implemented = <0x1>;
> + };
> +
> With sub-nodes:
> sata@f7e90000 {
> compatible = "marvell,berlin2q-achi", "generic-ahci";
> diff --git a/drivers/ata/ahci_platform.c b/drivers/ata/ahci_platform.c
> index 4044233..ec8db80 100644
> --- a/drivers/ata/ahci_platform.c
> +++ b/drivers/ata/ahci_platform.c
> @@ -42,6 +42,7 @@ static int ahci_probe(struct platform_device *pdev)
> struct device *dev = &pdev->dev;
> struct ahci_host_priv *hpriv;
> int rc;
> + u32 ports_impl;
>
> hpriv = ahci_platform_get_resources(pdev);
> if (IS_ERR(hpriv))
> @@ -51,6 +52,9 @@ static int ahci_probe(struct platform_device *pdev)
> if (rc)
> return rc;
>
> + of_property_read_u32(dev->of_node,
> + "ports-implemented", &hpriv->force_port_map);
> +
> if (of_device_is_compatible(dev->of_node, "hisilicon,hisi-ahci"))
> hpriv->flags |= AHCI_HFLAG_NO_FBS | AHCI_HFLAG_NO_NCQ;
>
> --
> 2.5.0
>
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